Answer:
t = 3.8 [s]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f} =v_{o} -a*t[/tex]
where:
Vf = final velocity = 5 [m/s]
Vo = initial velocity = 13 [m/s]
a = desacceleration = 2.1 [m/s²]
t = time [s]
As we can see in the above equation the acceleration is negative because the car slows down its velocity.
5 = 13 - 2.1*t
2.1*t = 13 - 5
t = (8)/2.1
t = 3.8 [s]
